All Might was floored at how easily All For One was handling him. The man had created clones of himself to attack the hero from every direction possible, chipping away at his strength. Despite the ever presence of the villain, All Might could not even identify him amidst the chaos. One was trying to drown him using electrified mercury and boiling lead while another was binding him using pressure capable of creating diamonds with one more amping himself up and delivering a punch containing multiple quirks to the hero's solar plexus. A cloud of neurotoxin surrounded All Might's orifices and photonic slashes stabbed into his skin.
But all left little real injury. All Might analyzed that the quirk variety being used here was lack-lustered, hinting at a possibility he could utilize: the process All For One had spoken about was not completed and he was buying time. Trying to pinpoint a particular target was impossible in the amount of time he wanted to allocate to this process so he just started dishing space rupture in every direction.
The hostage was made into a spear, a useless weapon for someone whose primary attack method was quirk-based.
'He needs that girl. So her quirk is useful. But what is it?' , All Might could not see the girl's face due to the height difference in their floating position.
"ALL FOR ONE!"
A shout shattered every clones of the villain but the real body was far gone. All For One knew that only the he in the present was unique and was capable of handling this divinity-soaked hero. He had already limited the number of quirks attacking All Might to test his theory: adaption.
'So some level of adaptation to attacks, what to what level? Conceptual against slashing? Or his body growing thicker skin to protect itself? But at this distance, he would need spatial jump to me. But that amount of time is enough!'
What All For One was toying with was the black airship he had brought to another dimension. He had checked and was sure that something familiar to him was inside this piece of steel. Prying off the black anti-quirk, anti-surveillance layer, he was disappointed seeing the flimsy material so he just used a quirk to sharped his fingernails before drawing a circle, cutting his way into the ship. This feeling ... space expansion technology.
Something pierced through his perception range and was right before his body. The quirk energy resembled himself but that was a concern for future him. He connected the space before and after him so the thing could go through without alerting the user if it failed. The plan failed as the linkage was destroyed and he was impaled in the chest. Now taking a closer look, he could see the dense energy forming the spear. With the assumption of an ambush, he calculated the basic quirk strength of this insolent fool without ever turning off his perception quirks.
'A few hundred of quirks worth of energy reserve. Someone with quirk similar to me most possibly. Where are they? And this space is large enough to house an entire city but why spend so much energy to maintain this expansion? Must be housing something inside. A guard and something of great value.'
All For One swung his right hand to the left, the walls in front of him were diced up and fell apart. Within his focused range, nothing stood a chance of going unnoticed. The moving parts tried to slide back in to repair the damage but they were promptly evaporated using lasers. As his move began to reach more and more places within the airship, he was alarmed and turned his body sideway midflight, dodging a spear of energy aiming for his head. He locked the space surrounding him.
"Looks who we got here. So a pawn of the World Government is taking its chance against me."
The culprit, a fully armored individual whose quirk All For One deduced to be letting them creating the energy spears, was in miserable state as their arms were broken and their leg nearly tore off from the sudden stop. Before All For One could rip the quirk from this attacker, they attacked back. All For One was surprised seeing how his spatial quirks were disabled before being docked in the face.
With one fist punching and drawing attention, the attacker created another spear before aiming it at All For One's heart. The man was quick enough to twist his body, scraping the spear a little. All For One could not use the quirks in his possession to counter since the condition for quirk limitation had not been found. Using a strength-enhancement quirk, he slapped the attacker deeper into the ship as he stood up and swiping some dust off his clothing. Soon the strength faded away from his grip.
'My quirk has already been amped up so its influence should be impossible to remove. So how can this guy do it? And lingering quirk-stripping effect... hah! It has been so long for this level of brainstorming. With this level of synchroneity with the quirk energy, I am hoping to save this for One For All. What a pity."
With a swing of his spear, the dimension collapsed and from outside, a black airship had steel structure broken through its body. The sudden appearance of the sphere drew All Might's attention and he was prying one beam away when he felt aching in the chest. Blood spewed from the wound as All For One had pierced All Might's heart.
\---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
The black airship was the main method that could provide enough power to kickstart the the technology utilized in this fight against All For One. Sensing the danger to All Might's live and the destruction of the power system fueling the charging station, the backup armor for All Might flew out of the wreckage and quickly reached the falling hero. The metal particles began to fill up any vacant skin area except for the face to provide proper protection while the life system checked All Might's body for the grave injury it had detected. Yet it found none.
"All For One...?"
"So I am weaker than this weapon? Ridiculous."
What flew before All Might was not the villainous mastermind he had wanted to kill for the improvement of the world. It was a pulsating mass of red trying to take over All For One's body and it all started from the spear the villain had crafted from that innocent girl.
"You will OBEY ME!"
The mass was returning to the spear.
"I'M YOUR CREATOR! AND YOU SHALL HEED MY WORDS!"
The final step was taken and the weapon had synchronize with All For One. He had been lucky to be testing this thing out before using it in a real fight, leading to the black airship being broken from within.
"ALL FOR ONE!"
Something broke through the wreckage below and flew to the same height as All Might. What could be seen was a war weapon specifically designed to counter quirk warlord, an Armored Core, or AC. The only thing that could crush a quirk warlord whose rise to power was their quirk must be something more powerful than even that. The humanoid figure was specifically designed for burst speed and light artillery. A triangular head with a row of cameras for eyes all locked onto the figure of All For One while the large-caliber rifles aimed straight at the villain's head.
"That thing ... It has been sometime since I last saw something like this in the Gobi Dessert in one of the demonstration. It was used for quick surveillance so maybe -BANG!"
"How impatient."
A bullet the size of All For One's head was stopped with a single finger before he flicked it away. The kinetic energy was collected and stored for more robust quirk output. And yet All For One had to still be careful. The material coating the mech, from his perspective, was coated in quirk energy so he was not hasty in applying any quirks to the mech itself. But for the environment... not possible. As the villain tried to lock the space surrounding the mech, it temporarily worked but with the bursting boosters behind, it broke free.
'A layer of anti-quirk. Just have to do it the old fashioned way.'
Though All For One as he kicked All Might toward the mech but the latter already repositioned to shoot at his head again. After the hero tried to take advantage of the villain's momentary lapse in concentration. he was beaten and sent away but quickly return by punching a hole in spacetime.
"Manhattan Smash!"
The punch entered a portal and landed on the mech swinging a plasma machete to bisect the villain. The mech missed but the shoulder missile launcher opened fire in proximity. The blinding light of a close range direction did not hinder All For One as he gripped the spear in his hand and separated the world in two, heavily damaging the first spatial isolation barrier.
Creating a field of ice spikes from the ocean beneath, All For One began firing them toward his opponents. All Might paid no intention to the attack but for the mech, it had to maneuvered and dodged everything since the anti-quirk property would remove the cause of motion, not the motion itself.
"Dance, to not be impaled!"
"You speak so highly for someone being pummeled by me."
An overhead hammer swing collided with All For One's head but the daze did not distract him from the goal he was aiming for. With a slash of the fleshy spear in his hand, One For All and the mech was sent faraway to the other end of Japan. The villain utilized that moment to brought the spear up before letting it absorbing the first spatial isolation barrier layer. The sky and the sea coiled around each other, all heading to ward the shaft. All For One could feel the link between him, the spear, and the source for quirk energy growing stronger.
"Again. Again."
The villain kept the final layer untouched in the process of unraveling the reality. With enough power stored, All For One's form began to change. His body elongated and twisted, limbs and organs began to grow inside him and from his back, thirteen wings of light pierced the spacetime, accelerating the process. Soon enough, a figure rivaling a city made its appearance into the world, its weapon enough to break through the concept of limit. Its first motion was to slice up All Might from the inside using super-dimensional approach.